What is this noise ?? (Intermittent hissing)

[bosse92m3]

Hey guys, drove my car today and after I parked it, I noticed a weird hissing/ air leaking noise coming from the right side of the engine bay.
Initially I thought it was coming from the front right tire, but upon listening to it more, it appeared to be coming from the engine bay.

I have searched and all I could find is people mentioning a sizzling sound but I believe this is different, it s much more like a hissing sound.

I have posted a video below of the noise.
What could it be?
Thanks in advance!!